Luminaire



l, 3 Sileets-Sheei 1 oca. r11 1921.

i A. DOREY LUMINAIRE Filed Feb'. 9. 1924 INVENTOR ATL..

/n/ v ATTORNEY Oct. 11.1927.

w. A. Dom-:Y

LUMINAIRE Filed Feb. 9. 1924 3 Sheets-Sheet 3 INVENTOR Daffy Patented @da 1l, i927.

NETE

WILLIAM A. DOREY,

OE NE'WARK, OrO, HOLOPHANE COMPANY, INC., OF NEVI YORK,

Assrenon, BYrv nnsnn AssrGnivE-Nrs, To

n. a coeroaafrron or NEW YORK.

LUMINAIRE.

Application filedl February The object of my invention is the construction of luminaires having transmitting covers or envelopes made up of a glass structure provided with prismatic corrugations adapted to give a selective distribution of light in longitudinal directions and either' uniform or selective distribution of light in lateral directions with some' degree of diffusion. This is accomplished by means of a construction provided' with concentric corrugations on a face of the glass adapted to selectively distribute the light in longitudinal directions and a cooperating construction having substantially parallel corrugations on a face of' theglass adapted to diffuse and distribute the light in 'lateral di rections.

The most important use of the invention is in building up luminaires ofV polygonal lantern form made up of compound light transmitting plates, in which the individual sections used may be of similar design so that in combination they produce a uniform lateral distribution of light or the individual sections may be of varying design so that in combination they produce a selective distribution in lateral directions or varying selective distributions in sepa-rate longitudinal planes. These are used in cases whe-re a considerable departure from the natural light distribution is required by the type of service and yet a definite indication of the lantern form is desired when the lu minaire is in operation.

The most obvious case is in streetlighting where great concentration is required in vertical planes slightly below the horizontall and a somewhat wider spread of light is required in lateral directions. Considering only the question of distribution of illumination to the area to be lighted, park lighting will usually require a substantially uniform lateral spread throughout 360 degrees. The lighting of streets by sources mounted over the curbs will require at the most a lateral spread through slightly more than one-half circle on the street side and in some such cases a greater restriction of the beam up and down the street is found to be of advantage. By proper design and location of the various plate members in the lantern, the requirement of park lighting can be takencare of and the variousrequirernents for lighting from street curbs can be met satisfactorily,

9, i924. serial No. 69135253.v

Fig. lis an elevation of one forni of mv invention. u

Fig. 2 is a' horizontal cross section through plane 2-2, Fig. l. Y

Fig. 3 is a vertical cross sectionl through plane 3 3, Fig. 2.

Fig. 4 is a normal view of one form of panel embodying myinvention;

Fig. 5 is a horizontal cross section of Fig. 4; y

Fig. 6 is a large size detail of a portion of Fig. 2;

Fig. 7I is a large size detail' of a portion of Fig. 5; and, o

Figs. 8, 9 and l() are large" size detail cross sections ofa specialform offreiecting .prism used in connection with my inve-ntion.

ln Figs. l, 2 and 3,8 is a lantern frame supporting the compound glass panels.A

lEach panel is made up of a rear plate 5 with a smooth; inner surface 6 and concentric prisms 7 on itsl front face and a front plate 8 with vertical flutes 9 on kits rear facel and a smooth front or outer surface 10. The flanges of inner and outer plates project above the; prism surfaces and are ground flat to seat against each other at 12. This ground joint may be gaslreted or cemented and the two plates fastened together so as to malte a. unit of the panel. The lateral edges of the plates are bevelled at 13 so as to include the greatest possible lateral angle of light on the prism surfaces. This bevel also assists in keeping the panels in place and in permitting easy removal 'for cleaning or replacement. 11- is the light source, consideredl as a point. In Fig. 3 the course of typical light rays in verticalfplanes is indicated by broken lines. The concentric prisms 7 on plate 5 are formed at such angles as to vproduce a conical beam of just sulficient divergence to meet the vertical dis-i l tribution requirements and this beam passes through the front plate 8 with ver-y little change in the vertical inclination ofy the light rays.- The course of typical light rays is shown in brokenlines'. From the-centreof the plate where the annular rings are continuous' and from the upperp'art'of the plate the emitted rays are substantially parallel .so asV to v produce the: high intensities required near theupper limit ofthev emitted beaml Froin'the' lower 'part ofthe plate the emittedl rays are of slightly increasing di'- Tfergen'ce as the bottom of the plate is appreached so as to provide the moderate 1ntensities require-d at lower angles. VIn effect A this modification in the action of the concentric prisms 7 produces a selective distribution of the light days in vertical orlongitudinal directions. In Fig. 2 the course of ypical light rays is indicated by broken lines. At 1li the outer plates are broken away near the edgeof two adjacent panels to show more clearly the function of theV erally. The action of these vertical flutes is also shown vinj larger scale in Fig. 6. Since the arcl of each successive prism in the lower part of the plate is a'smaller part ofv the completecjircleB the latera'l divergence across the face of the Vplate will increase very liti Vtle notwithstanding the increase in vertical divergence. rlliereforethe emitted rays may be considered as substantially parallel in any horizontal cross section and the vertical flutes8'may be made of thesame contour across the whole rear face of the plate and Ywill all produce substantially the same spreading effect on the beamfrom the inner plate. By use of the proper curved contour for the ilutes the beams from adjacent panels can be spread to overlap and produce substantially uniform intensities in latera'l planes. VSince the vertical flutes in each panel are of the same contour and their relation to the light incident upon them is substantially the same, the light `will appear to bespread uniformly across the face of each panel and thus the flat sided lantern form will be clearly indicated.A

In Figs. 1, 2 and 3 thelines from the light. sourceto the centersl ofeach concentric systemof prisms 71 is normal to the plate surface 6 and the vertical liutes are formed symmetrically with'reference to the plate surface 10. The resultant distribution of f light is therefore symmetrical with refer ence to all vertical planes through the vertical axis of the lantern and the centers of all the panels and due to the symmetrical lateral spreading effect of the vertical flutes 9 the distribution is substantially symmetritensity in other vertical planes. This lcan be accomplished to a moderate degree inmy construction by separate design cf the va- 1,6 las?? 4. 'lhe concentric prisms 18 are similar to thoseshown in Fie. 1 with the exception that theirv center 16 has been shifted vlaterally to the right with reference to light source 11.V A j y r1`he general direction of the cone of light emerging fromrear plate 5 will then be shifted laterally to the right with respect to the llight source. 1n Fig. 5 a portion of the front .plate S'has been broken away at 17 andV the directionof typical light -rays proceeding from rear plate 5 is shown by dotted lines. Y

The vertical flutes 19, Fig. 5 are of unifo m contour and siinilarto those shown in F ig. 2 eiaceptthat their axes are tilted so as to cool ente with the shifted prism system on the inner plate. The form of the vertical. Y

flutes and their action on typical light rays received from the inner plate is shown in large scale in Fig.l 7. Referring to Fig. .7, the axes 23-23 of the flutes 19 are inclined with reference to the normialto the plate surface and in the opposite direction to the inclination of the light rays Ql-Qtreceived from the inner glass. This reduces the flute surface refracting light to the left and tilts the balance of theflute surface operating to refract light to the left at a grazing angle with the incident light ray so that the pro-V portion of the light 'ays striking this surface isreduced `and the percentage of sun face reflection of the incident ray onto the opposite surface is increased. Therefore that portion of the flute contour refracting tothe right is mainly operated. l

Now if: apanel of this design be substitu'ted for one'of those shown in Fig. 2, the intensity nea-rthe normal'to that panel station will be reduced and the intensity near the norn'ial of the-next adjacent panel station on the right will be built up.

ln most cases where it is desirable to give a lateral shift to the light from certain panel stat-ions, `*the intensity will not be decreasedthrough a suiiicient lateral arc ifthe lantern bebuilt up solely from panels of the forni shcwn in Figs. 1, Q and 3 and the panels of the form shown in Figs. 4 and 5. l therefore make use of a third form of panel in `which the front plate is substantially the same as front plate 8. F ig. The rear .plate in this third panel form has concentric 'prisms similarly placed to prisms i fon rear plate 5 in Figs. 1, 2 and 3 but the conteur of the prisms 1s such as to reflect a porl tion nf the light back through the source to refract and scatter the balance in extreme upward and downward directions. The light reflected back through the source serves to intensify the beam from the plates on the oppositeside ofthe lantern.

Figs. 8, 9 and l0 show large size vertical cross sections of three typical portions of such a plate having special reflecting prisms of the form described. y All of these sections are made soas to show the transverse cross section of the prisms. Fig. 8 shows a portion of the upper part of the plate. Fig. 9 shows a portion of the central part of the plate. Fig. l shows a portion of the lower part of the plate. In all of these the action of typical light rays is shown in broken lines.

l have shown my construction with the concentric prism center located at the intersection of the normal to the plate passing through the light source and also with the concentric prism center shifted laterally from this position. 1n some cases an upward or downward or intermediate shift of this center may be required. Moreover the front plate of the panel shown in Fig. vmay be combined with the rear plate shown in Fig. 2 and the front plate in Fig. 2 may be combined with the rear plate in Fig. 5 to obtain lateral distributions intermediate between those sliown when such intermediate distributions are required.

l have shown in Fig. l panels which are integral from top to bottom but for convenience and economy in manufacture it is often desirable to use a double tier of panels in each panel station, the lower panel being similar .in design to the lower part of the panels shown in Fig. l and the upper panel imilar in design to the upper part of the panels shown in Fig. l. In such cases cross bars rest on the top of the lower tier to support the upper tier and to mask the flanges of both panel sections. By this means much larger pris-matic luminaires can be built than are practicable in the usual two or three piece forms. rl`his is of importance in ycases where it is desirable to reduce intrinsic brilliancy by delivering the light from a large surface and where it is desirable'to attain large size for ornamental purposes.

I have shown my invention built up in octagonal lantern form but it is applicable to square, pentagonal, hexagonal .-or other po-A lygonal forms and in some special cases can be used effectively in single panels.

iVhile my invention is especially adapted to separate panel constructions it is possible in small sizes to maire the rear or interior plates integral with each other and the outer plates integral with each other. Such integral constructions will usually have panel designs to shift the beam laterally of the general type shown in Figs. 4 and 5.

lVhile l have described my construction as filling all the panel stations in a lantern, it

can often `be used to advantage `for certain purposes in combinations with transmitting and reflecting glasses which do not involve lmyinvention. 7When the lantern is mounted on a bracket supported from af building front it willoften be found desirable to use on the building side one or morev panels made of opal glass or one or more panels having 'the interior plate of the prismatic reflecting construction previously Adescribed and with an outer plate of opal or other diffusing glass. i

lt will often be found desirable to use auxiliary diffusing transmitting glasses above or below the main lantern frame indicated in Fig. l or reflectors to catch the eXtreme upward and downward rays and redirect them to the prismatic panels.

l. A luminaire comprising a light source and a concentrating lens element having on an outward surface a series of concentric corrugations the part above the common centre being adapted to transmit light rays from the source in substantially parallel directions and the part below the common centre being adapted to transmit light rays from thc source in increasingly divergent directions as the distance from the common centre increases and a cooperating construe tion having on an inner surface a series of substantially straight parallel corrugations adapted to diffuse and distribute the light rays in transverse directions.

2. A luminaire comprising a light source and a concentrating lens element provided on an outward surface with aseries of concentric corrugations, the common centre of the corrugations being off-set from the normal of the element passing through the center of the light source, such corrugations being adapted to give a concentration of the light rays in the direction in which the common centre is off-set and a cooperating construction having on an inward surface a series of substantially straight parallel corrugations adapted to diffuse and distribute the light rays in lateral directions.

3 A luminaire comprising a light source and an enclosure consisting of a series of lens elements, each element having on an outward surface a series of curvilinear corrugations adapted to give a varying degree of concentration in longitudinal directions and on an inward opposed surface a series of straight parallel corrugations adapted to diffuse and distribute the light rays syin-4 metrically in transverse directions so that the spread beams from adjacent elements combine to produce substantially uniform distributions in all vertical planes. l

4. A luminaire comprising a light source, and an enclosure consisting of various lens elements, certain of these elements having on an outward surface a system of curvilinios ear corrugationsand on an inward opposed surface a series of straight parallel Corrugations, and adjacent thereto elements. of similar Construction in which the center of the system of curvilinear oorrugatons is olifset from the normal of the element passing through the center oi the light source to shift the'bearn transversely7 and the straight parallel corrugations having their planes of l@ symmetry tilted to spread theV beam asymmetrically, vthe beams of the Various elements combining to produce a distribution of increased intensity in certain VerticalV planesand a gradual dropping off of intenSit-y at either side of these planes.

Signed at Newark, in the county of Lickingvand State of Chio, this 7th day of February A1924.

VILLIAM A. DOREY. 

